Effect of Wrist Angulation on Radial Artery Sonoanatomy in a Pediatric Population: An Observational Pilot Study

The radial artery is the most preferred site for arterial cannulation in pediatric patients. The optimal wrist position which provides the largest size of the radial artery in pediatric patients is unknown.

We aimed to compare the sonoanatomy of the radial artery in different wrist positions (0°, 15°, 30°, 45°, 60°, and 75° extension) in pediatric patients to identify the optimal position which offered the largest diameter of the radial artery.

Ninety-six patients aged 1-12 years undergoing elective surgery were included. After induction of general anesthesia, an ultrasound examination of bilateral radial arteries was done. The wrist was placed in six different positions: 0°, 15°, 30°, 45°, 60°, and 75° extension, and radial artery anteroposterior diameter (APD), transverse diameter (TD), and depth from the skin (depth) were measured bilaterally using ultrasound.

The mean (±standard deviation [SD]) APD in the neutral wrist position was 1.79 (±0.45) mm and 1.76 (±0.47) mm on the right and left side, respectively. The mean (±SD) TD in the neutral wrist position was 2.32 (±0.47) mm and 2.35 (±0.68) mm on the right and left side, respectively. The mean (±SD) depth of the radial artery in the neutral wrist position was 1.75 (±0.70) mm and 1.65 (±0.76) mm on the right and left side, respectively. With increasing wrist angulation, both APD and TD did not show any significant change; however, depth decreased with increasing angulation. All measurements were comparable bilaterally.

In 1-12-year-old children, increasing wrist angulation leads to decreasing depth of the artery; however, the anteroposterior and Transverse diameter show no significant change.